Multiple studies have identified sensorimotor gating deficits in patients with schizophrenia, their first degree unaffected relatives, and in pharmacological and genetic mouse models of schizophrenia. These deficits in sensorimotor gating may serve as a hallmark endophenotype of the disorder. Here we propose to directly quantify the neurophysiological mechanisms that correspond with sensory gating in mice by implanting arrays of microelectrodes across 7 distinct brain areas comprising mesolimbic, mesocortical, and cortical-striatal-thalamic microcircuits and performing neurophysiological recordings as mice perform a classic sensorimotor gating task. We will then quantify the effect of the psychotomimetic agent PCP and the schizophrenia risk gene DISC1 on these circuit mechanisms. We believe that the insights derived from the current proposal into the distributed circuits that underlie normal sensorimotor gating, and the mechanisms whereby genetic and pharmacological manipulations disrupt these circuits, will provide a detailed network-level understanding of the neurophysiological alterations that may contribute to schizophrenia.